The International Association for Comparative Research on Leukemia and Related Diseases (IACRLRD) with offices at The Ohio State University Comprehensive Cancer Center, is requesting financial support from the National Cancer Institute for its XIIth International Symposium for Comparative Research on Leukemia and Related Diseases. These symposia are held every two years; the XIIth Symposium will be held at Congress Centrum in Hamburg, West Germany with Dr. Friedrich Deinhardt, President of the IACRLRD serving as host and program chairman. Funds are requested for the travel, meeting expenses, and registration fees of invited speakers, session chairpersons, moderators, and IACRLRD staff from the United States. No funds are requested for personnel. Expense of invited participants from Europe, Asia, Australia, and South America will be paid by other sources available to the IACRLRD and to Dr. Deinhardt. The XIIth Symposium will be held July 7 to July 12, 1985. The program will focus on progress in research in leukemia and lymphoma in the fields of cell biology, virology, immunology, chemical and biologic leukemogenesis, epidemiology, and therapy. Plenary sessions with an overview and indepth updates of selected topics within each field will be presented. Related workshops, conjoint poster sessions, and roundtable discussions will supplement the plenary sessions to provide detailed coverage of members own research projects.